The fate of glucose in different parts of the rabbit brain

Abstract

The fate of uniformly $^{14}$C labelled glucose has been followed by a quantitative application of the radio paper-chromatographic technique in different parts of the rabbit brain-hypothalamus medialis anterior, hypothalamus medialis posterior, hypothalamus lateralis anterior, cerebral cortex, cerebellar cortex-and in the optic chiasma. Qualitatively the metabolic pattern of glucose was similar in all the different parts of the brain which were studied. The glucose disappearing from the medium after 60 min of incubation was accounted for as lactic acid, CO$_{2}$, alanine, aspartic acid, glutamic acid, $\gamma $-aminobutyric acid and glutamine. However, in the cerebral cortex significantly greater quantities of alanine, aspartic acid, glutamic acid and glutamine were found than in any of the other tissues. The hypothalamus formed more $\gamma $-aminobutyric acid from glucose than the cerebral and cerebellar cortex. The inclusion of potassium in the medium augmented the oxygen uptake and the production of radioactive glutamine in all the different parts of the brain and the production of radioactive CO$_{2}$ in the cerebral cortex. On the other hand, the presence of potassium diminished the production of radioactive CO$_{2}$ in the hypothalamus but had no effect on CO$_{2}$ production in the cerebellar cortex.